3.9 How to upgrade packages from specific versions of Debian

apt-show-versions provides a safe way for users of mixed distributions to upgrade their systems without getting more of the less-stable distribution than they had in mind. For instance, it is possible to upgrade just your unstable packages by running after having installed the apt-show-versions package:

     # apt-get install `apt-show-versions -u -b | grep unstable | cut -d ' ' -f 1`